Jean-Philippe Vercruysse

The value of diffusion-weighted MR imaging in the diagnosis of primary acquired and residual cholesteatoma : a surgical verified study of 100 patients

Our goal was to determine the value of echo-planar diffusion-weighted MR imaging in detecting the presence of primary acquired and residual cholesteatoma. One hundred patients were evaluated by preoperative magnetic resonance (MR) imaging with diffusion-weighted MR imaging. The patient population consisted of a first group of 55 patients evaluated in order to detect the presence of a primary acquired cholesteatoma. In the second group, 45 patients were evaluated for the presence of a residual cholesteatoma 8–18 months after cholesteatoma surgery, prior to second-look surgery. Surgical findings were compared with preoperative findings on diffusion-weighted imaging (DWI). The sensitivity, specificity, positive and negative predictive values of both groups was assessed. In the group of primary surgery patients, hyperintense signal compatible with cholesteatoma was found in 89% of cases with a sensitivity, specificity, positive and negative predictive value for DWI of 81, 100, 100 and 40%, respectively. In the group of second-look surgery patients, only one of seven surgically verified residual cases was correctly diagnosed using DWI, with a sensitivity, specificity, positive and negative predictive values of 12.5, 100, 100 and 72%, respectively. These results confirm the value of DWI in detecting primary cholesteatoma, but show the poor capability of DWI in detecting small residual cholesteatoma.

Detection of postoperative residual cholesteatoma with non-echo-planar diffusion-weighted magnetic resonance imaging.

Objective: The aim of this study was to analyze the role of non-echo-planar imaging (non-EPI)-based diffusion-weighted (DW) magnetic resonance imaging (MRI) for the detection of residual cholesteatoma after canal wall-up mastoidectomy before eventual second-look surgery. Study Design: Prospective and blinded study. Setting: Tertiary referral center. Patients: The study group included the surgical, clinical, and imaging follow-up of 32 consecutive patients after primary cholesteatoma surgery. Interventions: All patients were investigated with MRI, including late postgadolinium T1-weighted sequence and non-EPI-DW sequence, 10 to 18 months after first-stage cholesteatoma surgery by experienced surgeons using a canal wall-up mastoidectomy. The non-EPI-DW images were evaluated for the presence of a high-signal intensity lesion consistent with residual cholesteatoma. Imaging findings were correlated with findings from second-stage surgery in 19 patients, clinical follow-up examination in 11 patients, and, in 2 patients, clinical and MRI follow-up examination. Results: Non-EPI-DW sequences depicted 9 of 10 residual cholesteatomas. The only lesion missed was a 2-mm cholesteatoma in an examination degraded by motion artifacts in a child. All other diagnosed cholesteatomas measured between 2 and 6 mm. Sensitivity, specificity, positive predictive value, and negative predictive value were 90, 100, 100, and 96%, respectively. Conclusion: Except for motion artifact-degraded examinations, non-EPI-DW MRI is able to detect even very small residual cholesteatoma after first-stage surgery by showing a high-signal intensity lesion. It has the capability of selecting patients for second-look surgery, avoiding unnecessary second-look surgery.

Mastoid and Epitympanic Bony Obliteration in Pediatric Cholesteatoma

Objective: The primary goal of cholesteatoma surgery is complete eradication of the disease. To lower the recurrence rate in the pediatric population in canal wall up techniques and to avoid the disadvantages of canal wall down techniques, the bony obliteration technique with epitympanic and mastoid obliteration has been developed. The objective of this study was to evaluate the long-term surgical outcome and recurrence rate of this technique in children. Study Design: Retrospective case review. Setting: Tertiary referral center. Patients: Fifty-two children (<16 yr) were operated on in 90.4% (n = 47) for a primary or recurrent cholesteatoma and in 9.6% (n = 5) for an unstable cavity. Intervention: In all cases, we closed the tympanoattical barrier and the posterior tympanotomy with sculpted cortical bone and then completed obliteration of the epitympanum and mastoid with bone pâté. A reconstruction of the middle ear was performed by means of an allograft tympanic membrane including the malleus handle and a sculpted allograft malleus or incus for columellar reconstruction. Main Outcome Measures: Recurrent rate; residual rate; functional outcome; hygienic status of the ear; long-term safety issues. Results: The mean follow-up time was 49.5 months (range, 12-101.3 mo). Recurrent cholesteatoma occurred in 1.9% (n = 1). Residual cholesteatoma was detected in 15.4% (n = 8) of the cases. Postoperative hearing results revealed a median gain on pure-tone averages of 14.3 dB and a median postoperative air-bone gap of 25.6 dB. Conclusion: The mastoid and epitympanic BOT is an effective technique to lower the recurrence rate of cholesteatoma in the pediatric population. Follow-up by magnetic resonance imaging provides a safe, noninvasive method for postoperative detection of residual cholesteatoma.

Imaging of the opacified middle ear

Middle ear opacification on imaging studies performed in a non-traumatic setting mostly reflects chronic inflammatory/infectious disease. In some of these patients an underlying cholesteatoma will be found. High-resolution computed tomography examinations and magnetic resonance imaging are often used in the work-out of the disease. High-resolution computed tomography of the opacified middle ear serves to describe the status of the ossicular chain, and its suspensory apparatus, as well as the status of the tympanic and mastoid wall. When ossicular erosions are visualized, the probability of a present cholesteatoma is about 90%. Whereas high-resolution computed tomography is not able to differentiate cholesteatoma from other types of opacification, magnetic resonance imaging is. The combined use of delayed post-Gd T1-weighted images and non-EPI based DWI seems to be the actual best option on this matter.

Diffusion-weighted magnetic resonance imaging of the temporal bone.

This paper summarizes the value of diffusion-weighted magnetic resonance imaging in the evaluation of temporal bone pathology. It highlights the use of different types of diffusion-weighted magnetic resonance imaging in the different types of cholesteatoma, prior to first stage surgery and prior to second look surgery. The value of diffusion-weighted magnetic resonance imaging in the evaluation of pathology of the apex of the petrous bone and the cerebellopontine angle is also discussed.

Long-term follow up after bony mastoid and epitympanic obliteration: radiological findings.

OBJECTIVE The canal wall up bony obliteration technique lowers the incidence of recurrent cholesteatoma, but carries the potential risk of obliterating residual cholesteatoma. The objective of this study was to report long-term follow-up radiological findings after performing a canal wall up bony obliteration technique procedure, in order to detect residual and/or recurrent cholesteatoma. PATIENTS Fifty-one patients presenting with a cholesteatoma or a troublesome cavity were operated upon using the canal wall up bony obliteration technique, and were evaluated by follow-up imaging a mean of 76.4 months post-operatively (range, 53.8-113.6 months). INTERVENTION All patients were evaluated with high resolution computed tomography and magnetic resonance imaging (including delayed contrast, T1-weighted imaging and non-echo-planar, diffusion-weighted imaging). RESULTS Imaging revealed the presence of one residual, one recurrent and one congenital petrosal apex cholesteatoma. On high resolution computed tomography, completely obliterated mastoid filled with bone was observed in 74.5 per cent (38/51) of patients, and an aerated middle-ear cavity in 64.7 per cent (33/51). High resolution computed tomography clearly detected any associated soft tissue present in the middle-ear cavity (18/51) and in the obliterated mastoids (13/51), but could not characterise this tissue. Non-echo-planar, diffusion-weighted magnetic resonance imaging clearly identified all three cholesteatomas, and differentiated them from other associated soft tissues. No cholesteatoma was found within the obliterated mastoids. CONCLUSION Long-term follow up indicated that the canal wall up bony obliteration technique is a safe method with which to treat primary and recurrent cholesteatoma and to reconstruct unstable cavities. Soft tissue was found quite often in the middle ear and obliterated mastoids. High resolution computed tomography identified its presence but could not further characterise it. However, non-echo-planar, diffusion-weighted magnetic resonance imaging succeeded in differentiating soft tissues, enabling detection of residual or recurrent cholesteatoma after a canal wall up bony obliteration technique procedure.

Stapedotomy with Microdrill or Carbon Dioxide Laser: Influence on Inner Ear Function

Objectives: A prospective randomized audiological analysis of 336 otosclerosis operations was conducted to compare the evolution of bone conduction thresholds after primary stapedotomy with Two different techniques to open the footplate: microdrill and carbon dioxide laser stapedotomy. Methods: To monitor the inner ear function, we compared the preoperative bone conduction thresholds with the postoperative levels at day 2, week 2, week 6, and month 6. Evolution of the bone conduction was compared for the Two studied groups (laser versus microdrill). Results: An average bone conduction loss of 1.8 dB was measured at day 2 for the middle frequencies (0.5, 1, and 2 kHz). At 4 kHz, a bone conduction loss of 7 dB was found. The bone conduction thresholds measured in the first and second months after surgery showed a gradual recovery with overclosure as the end result. Conclusions: Our results confirm the transient depression of inner ear function in the immediate postoperative period, with recovery within the first weeks after surgery. In the studied population, no statistically significant difference was found between the Two techniques that were used to make the calibrated hole (laser versus microdrill). These results demonstrate that both techniques possess the same early effect regarding inner ear function. The authors hypothesize that an early inflammatory reaction could be the cause of the transient bone conduction shift.

Imaging of temporal bone tumors.

Tumoral lesions of the temporal bone are relatively rare. Cross-sectional imaging plays an important role in the description of extension of these lesions. In certain lesions, imaging characteristics are rather specific, giving a clue to diagnosis. The most common tumoral lesions of the external, middle, and inner ear are discussed. Some rare lesions are also highlighted.

Pathology of the vestibulocochlear nerve

There is a large scala of pathology affecting the vestibulocochlear nerve. Magnetic resonance imaging is the method of choice for the investigation of pathology of the vestibulocochlear nerve. Congenital pathology mainly consists of agenesis or hypoplasia of the vestibulocochlear nerve. Tumoral pathology affecting the vestibulocochlear nerve is most frequently located in the internal auditory canal or cerebellopontine angle. Schwannoma of the vestibulocochlear nerve is the most frequently found tumoral lesion followed by meningeoma, arachnoid cyst and epidermoid cyst. The most frequently encountered pathologies as well as some more rare entities are discussed in this chapter.

The Use of Malleus Allografts in Ossiculoplasty

Objective To assess the functional performance of remodeled malleus allografts in a malleus‐footplate assembly in terms of hearing results and mid long‐term stability.